<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="../react18/react.development.js"></script>
    <script src="../react18/react-dom.development.js"></script>
    <script src="../react18/babel.min.js"></script>
</head>

<body>
    <div id="app"></div>
    <script type="text/babel">
        class App extends React.Component {
            state = {
                count: 0,
                isHot: true
            }
            render() {
                const {count,isHot} = this.state
                return (
                    <div>
                        <button onClick={this.handle}>+</button>
                        <p>{count}</p>

                        <button onClick={this.changeWeaHandle}>切换天气</button>
                        <p>{isHot ? "热啊" : "冷啊"}</p>
                    </div>
                )
            }
            //事件函数
            handle = () => {
                let { count } = this.state
                this.setState({ count: count + 1 })
                // this.setState({ count: ++count })
                // this.setState({ count: count++ })//没被赋值.永远都是从零开始
            }

            changeWeaHandle = () => {
                const { isHot } = this.state;
                this.setState({ isHot: !isHot })
            }
        }

        const root = ReactDOM.createRoot(document.getElementById('app'));
        root.render(<App />)

    </script>
</body>

</html>